Cascade pump device

ABSTRACT

A cascade pump device may include a pump chamber, an impeller, a magnetic drive mechanism structured to rotate the impeller, and a pump case. The pump case is provided with two end faces located at both ends in an axial line direction and an intermediate part between the two end faces. The intermediate part is provided with a suction pipe and a discharge pipe and a wiring outlet part for taking out wiring lines for supplying an exciting current to a drive coil of a motor. The suction pipe and the discharge pipe are protruded in the same direction and the wiring outlet part is provided with a wiring line drawing-out guide part which determines a drawing-out direction of the wiring lines to the outer side. An angle between the drawing-out direction and a protruding direction of the suction pipe and the discharge pipe is less than 90° around the axial line.

CROSS REFERENCE TO RELATED APPLICATION

The present invention claims priority under 35 U.S.C. §119 to Japanese Application No. 2011-162571 filed Jul. 25, 2011 and Japanese Application No. 2012-140150 filed Jun. 21, 2012, the entire content both of which are incorporated herein by reference.

FIELD OF THE INVENTION

At least an embodiment of the present invention may relate to a cascade pump device in which a suction pipe and a discharge pipe in communication with a pump chamber are protruded in parallel to each other from a side face of a pump case.

BACKGROUND

A cascade pump device for pressure-feeding liquid which is referred to as a vortex pump or a cascade pump is described in Japanese Patent Laid-Open No. 2004-176659. The cascade pump device described in the patent literature includes a pump chamber, an impeller, a magnetic drive mechanism which rotationally drives the impeller by exciting a drive coil, and a pump case on which these structural members are mounted. The pump case is formed in a flat cylindrical shape and a suction pipe and a discharge pipe in communication with the pump chamber are protruded in parallel to each other from a side face of the pump case. The magnetic drive mechanism in the above-mentioned literature is a motor. A cable for supplying an exciting current to the drive coil of the motor is drawn out to an outer side in a radial direction from a lower end face of the pump case on which the motor is disposed. The drawing-out position of the cable in the literature is set to be an opposite side to the suction pipe and the discharge pipe and a protruding direction of the suction pipe and the discharge pipe and the drawing-out direction of the cable are opposite to each other.

In order to mount the cascade pump device described in the patent literature on an external apparatus, a space for drawing out pipes such as a hose connected to the suction pipe and the discharge pipe is required on one side of the pump case and another space is required on the other side which is an opposite side to the one side for extending the wiring lines drawn out from the pump case. Therefore, a large mounting space for the cascade pump device is required.

SUMMARY

In view of the problem described above, at least an embodiment of the present invention may advantageously provide a cascade pump device whose mounting space can be compact.

According to at least an embodiment of the present invention, there may be provided a cascade pump device including a pump chamber which is formed in a circular ring shape, an impeller which is formed in a circular ring shape and is coaxially disposed within the pump chamber, a magnetic drive mechanism which is structured to rotate the impeller by exciting a drive coil, and a pump case which accommodates the pump chamber, the impeller and the magnetic drive mechanism. The pump case is provided with two end faces which are located at both ends in an axial line direction and an intermediate part between the two end faces, and the intermediate part is provided with a suction pipe and a discharge pipe which are in communication with the pump chamber and a wiring outlet part for taking out a wiring line for supplying an exciting current to the drive coil to an outer side. The suction pipe and the discharge pipe are protruded in the same direction which is parallel to each other along a plane perpendicular to an axial line, and the wiring outlet part is provided with a wiring line drawing-out guide part which determines a drawing-out direction of the wiring line to the outer side, and an angle between the drawing-out direction and a protruding direction of the suction pipe and the discharge pipe is less than 90° around the axial line.

According to at least an embodiment of the present invention, the suction pipe and the discharge pipe which are extended in parallel to each other and the wiring outlet part are provided between two end faces located at both ends in an axial line direction of the pump case, and a drawing-out direction of the wiring line to an outer side through the wiring outlet part is set to be less than 90° around the axial line with respect to the protruding direction of the suction pipe and the discharge pipe. Therefore, in order to mount the cascade pump device on an external apparatus, it is sufficient that a space for drawing out pipes such as a hose connected with the suction pipe and the discharge pipe and a space for drawing out the wiring line drawn out from the pump case are provided on one side of the pump case. In other words, a space for drawing out the wiring line is not required on the other side of the pump case and thus the mounting space can be restrained. Further, according to at least an embodiment of the present invention, the wiring outlet part is provided at an intermediate part between two end faces located at both ends in the axial line direction of the pump case and thus the wiring line is taken out within a range of the height in the axial line direction of the pump case. Therefore, a space for drawing out the wiring line is not required at a position adjacent to the pump case in the axial line direction and thus the mounting space is restrained.

In at least an embodiment of the present invention, it is preferable that the suction pipe, the discharge pipe and the wiring outlet part are provided around the axial line in an order of the suction pipe, the discharge pipe, and the wiring outlet part, or in an order of the discharge pipe, the suction pipe, and the wiring outlet part. According to this structure, an angle around the axial line from the suction pipe to the discharge pipe is set to be large in a cascade pump device provided with the circular ring-shaped impeller and the pump chamber and thus a pressure for pressure-feeding liquid is enhanced. Therefore, even when the wiring outlet part for drawing out the wiring line is provided toward the protruding direction of the suction pipe and the discharge pipe, increase of the size of the pump case can be restrained.

In at least an embodiment of the present invention, it is preferable that the intermediate part is provided with an outer peripheral face structuring a contour of the pump case when viewed in the axial line direction, and the wiring outlet part is provided on an inner side with respect to the outer peripheral face which structures the contour. In other words, the wiring outlet part is disposed on an inner side with respect to the contour of the pump case when viewed in the axial line direction. According to this structure, when the wiring line taken out from the wiring outlet part is to be drawn out, a space for drawing out the wiring line near the contour of the pump case can be made small and thus, when the cascade pump device is to be mounted, an interference of an external apparatus with the wiring line can be restrained.

In at least an embodiment of the present invention, it is preferable that the intermediate part is provided with a first side face and a second side face, which are adjacent to each other around an axial line and structure a part of a contour of the pump case when viewed in the axial line direction, and a first projecting corner which is formed between the first side face and the second side face, and that the magnetic drive mechanism is structured on an inner side in a radial direction with respect to the pump chamber, and that the suction pipe and the discharge pipe are protruded from the first side face, and that the wiring outlet part is provided on an inner side with respect to the first projecting corner. When the pump case is provided with a projecting corner, a dead space is formed between the circular ring-shaped pump chamber and the projecting corner. Therefore, when the wiring outlet part is provided by utilizing the dead space, the size of the pump case is not increased.

In at least an embodiment of the present invention, it is preferable that the first projecting corner is formed with an inclined face extending in the axial line direction and intersecting with the first side face and the second side face by cutting out a tip end of the first projecting corner. According to this structure, the wiring line taken out through the wiring outlet part can be drawn out in the axial line direction along the inclined face. Further, the wiring line drawn out along the inclined face can be located on an inner side of the contour of the projecting corner structured of the first side face and the second side face when the pump case is viewed in the axial line direction.

In this case, it is preferable that the intermediate part is provided with a wiring line direction restricting part which restricts a direction of the wiring line drawn out along the inclined face after the wiring line is taken out from the wiring outlet part to an outer side of the pump case, and the wiring line direction restricting part is located on an inner side of a contour of a projecting corner structured by extending and intersecting the first side face and the second side face with each other. According to this structure, the wiring line drawn out through the inclined face and the wiring line direction restricting part can be prevented from interfering with an external apparatus when the cascade pump device is to be mounted.

Further, in this case, it is preferable that the wiring line direction restricting part is extended in a direction perpendicular to the axial line along the inclined face at a midway position in the axial line direction of the inclined face. According to this structure, when the wiring line which is drawn out along the inclined face and is extended through the wiring line direction restricting part is to be bent at a portion contacted with the wiring line direction restricting part in a direction separated from the pump case by utilizing the wiring line direction restricting part, the wiring line can be bent and extended at a position which is not protruded from a range of the height in the axial line direction of the pump case, in other words, at a position between two end faces located at both ends in the axial line direction of the pump case.

In at least an embodiment of the present invention, it is preferable that the pump case is formed in a rectangular prism shape. In the pump case formed in a rectangular prism shape, a corner portion with respect to the circular ring-shaped pump chamber is a dead space. Therefore, when the wiring outlet part is provided by utilizing the dead space, the size of the pump case is not increased.

In this case, it is preferable that the first projecting corner is formed with an inclined face which intersects the first side face and the second side face and is extended in the axial line direction by cutting out a tip end of the first projecting corner, and that the intermediate part is provided with a wiring line direction restricting part which restricts a direction of the wiring line drawn out along the inclined face after the wiring line is taken out from the wiring outlet part to an outer side of the pump case, and that the wiring line direction restricting part is a hook having a space for locking the wiring line between the inclined face and the hook and is located on an inner side of a contour of a projecting corner which is formed by extending and intersecting the first side face and the second side face each other. According to this structure, the wiring line can be bent and extended by utilizing the hook at a position which is not protruded from a range of the height in the axial line direction of the pump case, in other words, at a position between two end faces located at both ends in the axial line direction of the pump case to be drawn out in a direction separated from the pump case.

In at least an embodiment of the present invention, it is preferable that attaching holes for attaching the pump case to an external apparatus are formed in the pump case so that one of the attaching holes is formed on an inner side of a second projecting corner between the first side face and a third side face adjacent to the first side face on an opposite side to the second side face around the axial line and another of the attaching holes is formed on an inner side of a third projecting corner located at a diagonal position to the second projecting corner. According to this structure, each of the attaching holes is provided by utilizing a projecting corner which is a dead space with respect to the circular ring-shaped pump chamber in a pump case formed in a rectangular prism shape and thus, even when an attaching hole is provided, the size of the pump case is not increased.

Further, in at least an embodiment of the present invention, it is preferable that the pump case includes a first case and a second case, and that the pump chamber is partitioned by superposing the first case and the second case on each other in a partially overlapped state in a direction perpendicular to the axial line, and that the pump case is provided with a first fixing part for fixing the first case and the second case to each other with a screw, and that the first fixing part is protruded from the first side face between the suction pipe and the discharge pipe. A portion between the suction pipe and the discharge pipe is a dead space when the cascade pump device is attached to an external apparatus and thus, in a case that the first fixing part is protruded at this position, when the cascade pump device is to be mounted on the external apparatus, the first fixing part does not interfere with the external apparatus.

In this case, it is preferable that a second fixing part and a third fixing part are provided in the pump case for fixing the first case and the second case to each other with a screw, and that the second fixing part is formed on an inner side of the third projecting corner and the third fixing part is formed on an inner side of the fourth projecting corner located at a diagonal position to the first projecting corner. According to this structure, the second fixing part and the third fixing part are provided by utilizing a corner portion which is a dead space with respect to the circular ring-shaped pump chamber in the pump case formed in a rectangular prism shape and thus, even when the second fixing part and the third fixing part are provided, the size of the pump case is not increased.

In this case, it is preferable that the pump case includes a first case and a second case, and that the pump chamber is partitioned by superposing the first case and the second case on each other in a partially overlapped state in a direction perpendicular to the axial line, and that an O-ring is coaxially disposed with the pump chamber between the first case and the second case for preventing leakage of fluid from the pump chamber, and that a turning prevention mechanism is structured on an inner side of a fourth projecting corner located at a diagonal position to the first projecting corner in the pump case for preventing the first case and the second case from relatively turning to each other around the axial line when the first case and the second case are to be superposed on each other to partition the pump chamber. When an O-ring is twisted in a circumferential direction in a pressurized state, the O-ring may be damaged. However, according to an embodiment of the present invention, the first case and the second case are prevented from relatively turning to each other around the axial line by the turning prevention mechanism. Therefore, damage of the O-ring is prevented or restrained when the pump chamber is to be partitioned. Further, the turning prevention mechanism is provided by utilizing a corner portion which is a dead space with respect to the circular ring-shaped pump chamber in the pump case formed in a rectangular prism shape and thus, even when the turning prevention mechanism is provided, the size of the pump case is not increased.

Other features and advantages of the invention will be apparent from the following detailed description, taken in conjunction with the accompanying drawings that illustrate, by way of example, various features of embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will now be described, by way of example only, with reference to the accompanying drawings which are meant to be exemplary, not limiting, and wherein like elements are numbered alike in several Figures, in which:

FIGS. 1( a), 1(b) and 1(c) are perspective views and a front view showing a cascade pump device in accordance with an embodiment of the present invention.

FIGS. 2( a) and 2(b) are cross-sectional views showing a cascade pump device in accordance with an embodiment of the present invention.

FIG. 3 is an exploded perspective view showing a cascade pump device in accordance with an embodiment of the present invention.

FIG. 4( a) is a perspective view showing a rotor and FIG. 4( b) is a perspective view showing a stator.

FIGS. 5( a) and 5(b) are perspective views showing a lower case.

FIGS. 6( a) and 6(b) are perspective views showing an upper case.

FIG. 7 is a sectional view showing a part of a cascade pump device before an upper case and a lower case are superposed on each other.

FIGS. 8( a), 8(b) and 8(c) are explanatory views showing a state that lead wires (wiring lines) are drawn out.

FIGS. 9( a) and 9(b) are explanatory views showing a state that a cascade pump device is attached to an external apparatus by using a fixing member.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A cascade pump device in accordance with an embodiment of the present invention will be described below with reference to the accompanying drawings. In the following description, for convenience of explanation, upper and lower sides of a cascade pump device are described according to an upper and lower direction in the drawing. Further, a side from which a suction pipe and a discharge pipe are protruded is referred to as a front side of the cascade pump device and its opposite side is referred to as a rear side and an arrangement direction of the suction pipe and the discharge pipe is referred to as a widthwise direction of the device.

(Entire Structure)

FIG. 1( a) is a perspective view showing a cascade pump device in accordance with an embodiment of the present invention which is viewed from a forward oblique upper side, FIG. 1( b) is a perspective view showing the cascade pump device which is viewed from a rearward oblique upper side, and FIG. 1 (c) is a front view showing the cascade pump device. A cascade (vortex) pump device 1 in accordance with an embodiment of the present invention pressure-feeds liquid such as refrigerant. The cascade pump device 1 is provided with a pump case 2 which is formed in a rectangular prism shape as a whole. The pump case 2 is made of resin such as PPS (polyphenylene sulfide).

The pump case 2 is provided with an upper face (end face) 2 a which is located at an upper end in an axial line “L” direction, an under face (end face) 2 b which is located at a lower end in the axial line “L” direction, and an intermediate part 2 z located between the upper face 2 a and the under face 2 b. The intermediate part 2 z is provided with, as an outer peripheral face structuring a contour of the pump case 2 when viewed on the axial line “L” direction, a front face (first side face) 2 c which is a side face on the front side of the cascade pump device 1, a side face (second side face) 2 d on the left side in the widthwise direction of the device, a side face (third side face) 2 e on the right side in the widthwise direction, and a side face (fourth side face) 2 f on the rear side. Corner portions 2 g, 2 h, 2 i and 2 j between the front face 2 c and the side face 2 d on the left side, between the front face 2 c and the side face 2 e on the right side, between the side face 2 d on the left side and the side face 2 f on the rear side, and between the side face 2 e on the right side and the side face 2 f on the rear side are respectively formed to be a projecting corner which is a corner projecting to an outer side. The contour of the pump case 2 when viewed in the axial line “L” direction is set to be in the widthwise direction of the device and the length direction which are perpendicular to the axial line “L” of the pump case 2.

A suction pipe 3 and a discharge pipe 4 are protruded in parallel toward the front side from the front face 2 c of the pump case 2. A wiring outlet part 6 for taking out lead wires (wiring lines) 5 from an inner side of the pump case 2 is provided at a corner portion (inner side of a first projecting corner) 2 g on the front left side between the front face 2 c of the pump case 2 and the side face 2 d adjacent to the front face 2 c in the clockwise direction around the axial line “L” when viewed from a side of the upper face 2 a.

The lead wires 5 are drawn out from a midway position in the axial line “L” direction (height direction) of the cascade pump device 1 through the wiring outlet part 6 toward an obliquely front side. The lead wire 5 is extended longer than the suction pipe 3 and the discharge pipe 4 and a connector 7 is attached to tip ends of the lead wires 5. In this embodiment, as shown in FIG. 1( c), the suction pipe 3, the discharge pipe 4 and the wiring outlet part 6 are provided in the intermediate part 2 z between the upper face 2 a and the under face 2 b which are located at both ends in the axial line “L” direction of the pump case 2. In other words, the suction pipe 3, the discharge pipe 4 and the wiring outlet part 6 are provided at positions within the height of the pump case 2. Further, when the pump case 2 is viewed in a protruding direction of the suction pipe 3 and the discharge pipe 4, the suction pipe 3, the discharge pipe 4 and the wiring outlet part 6 are provided at visible positions.

An inclined face 2 k intersecting the front face 2 c and the side face 2 d and extending in the axial line “L” direction is formed at the corner portion 2 g located on the front left side of the pump case 2 where the wiring outlet part 6 is provided by obliquely cutting out a tip end of the corner portion 2 g. Further, a hook 8 is provided at the corner portion 2 g located on the front left side for restricting a direction of the lead wires 5 when the lead wires 5 are drawn out along the inclined face 2 k. The hook 8 is extended in a direction perpendicular to the axial line “L” along the inclined face 2 k at a center position in the axial line “L” direction of the inclined face 2 k. Further, the hook 8 is extended with a constant width from the front face 2 c side to the side face 2 d and a space for locking the lead wires 5 is formed between the inclined face 2 k and an inclined face 2 k side of the hook 8. When the lead wires 5 drawn out along the inclined face 2 k are locked by the hook 8, floating of the lead wires 5 from the inclined face 2 k is prevented and the position of the lead wires is determined. Further, when the lead wires 5 drawn out along the inclined face 2 k are locked by the hook 8, a drawing direction of the lead wires 5 is determined to an under side along the inclined face 2 k. In other words, the hook 8 functions as a wiring line direction restricting part which restricts a drawing-out direction of the lead wires 5.

An attaching hole 9 for attaching the cascade pump device 1 to an external apparatus is formed at a corner portion on the front right side (inner side of the second projecting corner) 2 h between the front face 2 c and the side face 2 e adjacent to the front face 2 c in the counterclockwise direction and at a corner portion on the rear left side (inner side of the third projecting corner) 2 i located at a diagonal position to the corner portion 2 h.

Further, the pump case 2 is structured of a lower case (one of a first case and a second case) 11 and an upper case (the other of a first case and a second case) 12 which are superposed on each other in the upper and lower direction. The suction pipe 3 and the discharge pipe 4 are protruded from the front face of the lower case 11. The wiring outlet part 6 is provided at the corner portion on the front left side of the upper case 12. The hook 8 is provided on the lower case 11. The lower case 11, the suction pipe 3, the discharge pipe 4 and the hook 8 are made of resin and are integrally formed with each other by molding.

In this embodiment, a corner portion 2 j (inner side of a fourth projecting corner) on the rear right side of the pump case 2 which is located at a position diagonal to the wiring outlet part 6 is provided with a turning prevention mechanism 13 (see FIG. 1( b)) for preventing relative turning when the lower case 11 and the upper case 12 are superposed on each other Further, a case fixing part (first fixing part) 14 is provided between the suction pipe 3 and the discharge pipe 4 of the pump case 2 so as to protrude from the front face 2 c. The case fixing part 14 is a portion where the lower case 11 and the upper case 12 are fixed to each other by using a screw 15.

FIG. 2( a) is a longitudinal sectional view showing the cascade pump device 1 which is cut by the “X-X” line in FIG. 1( a) and FIG. 2( b) is a longitudinal sectional view showing the cascade pump device 1 which is cut by the “Y-Y” line in FIG. 1( a). FIG. 3 is an exploded perspective view showing the cascade pump device 1. FIG. 4( a) is a perspective view showing a rotor and FIG. 4( b) is a perspective view showing a stator.

As shown in FIGS. 2( a) and 2(b) and FIG. 3, the lower case 11 and the upper case 12 are superposed on each other in a partially overlapped state in a direction perpendicular to axial line “L”. A partitioned chamber 20 is structured between the lower case 11 and the upper case 12. A rotor 23 provided with a circular ring-shaped impeller 21 and a drive magnet 22 and a support shaft 24 which rotatably supports the rotor 23 are disposed in the partitioned chamber 20. Further, an outer peripheral side portion of the partitioned chamber 20 is structured to be a circular ring-shaped pump chamber 25 and the impeller 21 is disposed within the pump chamber 25. An O-ring 26 is disposed between the lower case 11 and the upper case 12 for preventing leakage of fluid from the partitioned chamber 20. On an upper side of the upper case 12, in other words, on an opposite side to the partitioned chamber 20 with respect to the upper case 12 (opposite side to the lower case 11), a stator 29 provided with a drive coil 27 and a stator core 28, on which the drive coil 27 is mounted, and a base plate 30 on which electronic elements for controlling an exciting current to the drive coil 27 are mounted are disposed. The drive magnet 22, the stator core 28, and the drive coil 27 wound around the stator core 28 structure a magnetic drive mechanism for rotationally driving the impeller 21. The magnetic drive mechanism is structured on an inner peripheral side of the pump chamber 25 with respect to the axial line “L”.

A liquid flow passage 31 is formed on a bottom face and a ceiling face of the pump chamber 25 over a predetermined angular range around the axial line “L”. More specifically, a lower side fluid flow passage 31 a formed of a circular arc groove having a semicircular cross-sectional shape is formed on the bottom face of the pump chamber 25 which is structured of the lower case 11, and an upper side fluid flow passage 31 b formed of a circular arc groove having a semicircular cross-sectional shape is formed on the ceiling face of the pump chamber 25 which is structured of the upper case 12. The lower side fluid flow passage 31 a and the upper side fluid flow passage 31 b are superposed on each other when viewed in the axial line “L” direction. In this embodiment, the liquid flow passage 31 is formed over an angular range approximately larger than 270° around the axial line “L”.

In the pump chamber 25, a suction port 3 a (see FIG. 5( a)) which is in communication with the suction pipe 3 is provided at a portion of the lower case 11 where one end of the liquid flow passage 31 is located. Further, a discharge port 4 a (see FIG. 5( a)) which is in communication with the discharge pipe 4 is provided at a portion of the lower case 11 where the other end of the liquid flow passage 31 is located. A portion of the bottom face of the pump chamber 25 which is located between the suction port 3 a and the discharge port 4 a is formed as a lower side blocking part 32 a where the lower side fluid flow passage 31 a is not formed. Similarly, a portion of the ceiling face of the pump chamber 25 which is located between the suction port 3 a and the discharge port 4 a is formed as an upper side blocking part 32 b where the upper side fluid flow passage 31 b is not provided.

A support shaft 24 is made of stainless steel and its lower end portion is fixed to a support shaft fixing recessed part 60 which is provided in the lower case 11. Further, an upper end portion of the support shaft 24 is fixed to a support shaft fixing recessed part 82 which is provided at a center of a bottom part 81 of a center protruded part 80 formed in a bottomed tube-like shape that is provided at the center portion of the upper case 12. A height dimension in the axial line “L” direction of the pump case 2 is a dimension from an under face 2 b which is a bottom face of the lower case 11 to an upper face 2 a of the upper case 12. In this embodiment, the height dimension is substantially a total of a height dimension of the support shaft 24, a thickness dimension from the under face 2 b of the lower case 11 to the bottom face of the support shaft fixing recessed part 60, and a thickness dimension from an upper face of the bottom part 81 of the center protruded part 80 to a bottom face of the support shaft fixing recessed part 82 and the cascade pump device 1 is structured small in the axial line direction. The upper face 2 a of the upper case 12 is an upper end face of a frame-shaped outer peripheral wall 86 formed in the upper case 12 and a flat face around an upper end opening of the attaching hole 9 which is formed at the corner portion 2 h on the front right side and the corner portion 2 i on the rear left side of the pump case 2 is a part of the upper face 2 a.

The rotor 23 is provided with, as shown in FIG. 4( a), a disk part 40, a bearing part 41 in a cylindrical tube shape which is protruded upward from a center of an upper face of the disk part 40, and a cylindrical tube part 42 which is protruded upward from the upper face of the disk part 40 so as to coaxially surround the bearing part 41 with a predetermined distance from the bearing part 41, which are made of resin such as PPS. The predetermined distance between the bearing part 41 and the cylindrical tube part 42 is a distance in which the stator 29 is capable of being accommodated therebetween through the upper case 12. The rotor 23 is rotatable around the axial line “L” of the support shaft 24 in a state that the support shaft 24 is inserted into a center hole 41 a of the bearing part 41 and the bearing part 41 is disposed on an inner side of the center protruded part 80 of the upper case 12. One piece or plural pieces of washer 43 is fitted between the bearing part 41 and the bottom part 81 of the center protruded part 80 and the position of the rotor 23 in the axial line “L” direction with respect to the stator 29 is adjusted by fitting of the washer 43 (see FIGS. 2( a) and 2(b)). In this embodiment, two pieces of washer are inserted. For example, when one or two pieces of a washer 43 whose thickness is 0.2 mm and a washer 43 whose thickness is 0.3 mm are selected, a total thickness of the washers 43 can be adjusted in a range from 0.2 mm to 0.6 mm with an interval of 0.1 mm.

A yoke 44 in a cylindrical tube shape is held by an inner peripheral face of the cylindrical tube part 42 and the drive magnet 22 in a cylindrical tube shape is held by an inner peripheral face of the yoke 44. The yoke 44 is integrally formed with the rotor 23 by insert molding and the drive magnet 22 is adhesively fixed to the yoke 44. In the disk part 40 which is disposed on a side of the lower case 11, the impeller 21 is formed on an outer peripheral portion on an outer peripheral side of the disk part 40 with respect to the cylindrical tube part 42.

An outer peripheral portion of the impeller 21 is formed with recessed parts 45 which are formed in two rows in the upper and lower direction with an equal angular interval in the circumferential direction. The recessed parts 45 are provided with upper side recessed parts 46, which are formed by cutting a circumferential edge of an upper face of the disk part 40 in a circular arc shape, and lower side recessed parts 47 which are formed by cutting a circumferential edge of an under face of the disk part 40 in a circular arc shape. Portions between the recessed parts 45 adjacent to each other in the circumferential direction are formed as blades 48 which are respectively extended in a radial direction. A portion between the upper side recessed parts 46 and the lower side recessed parts 47 which are adjacent to each other in the upper and lower direction is extended in the circumferential direction and is formed to be a rib 49 partitioning the respective blades 48 in the upper and lower direction. The impeller 21 is, as shown in FIGS. 2( a) and 2(b), inserted into the pump chamber 25.

The stator 29 is disposed within a stator accommodating room 83 in a circular ring-shaped recessed part which is provided on an outer peripheral side of the center protruded part 80 and on an upper face side of the upper case 12. A stator core 28 is, as shown in FIG. 4( b), provided with a ring-shaped part 50 on its center side and a plurality of salient poles 51 which is protruded from the ring-shaped part 50 to an outer side in the radial direction. A drive coil 27 is wound around each of a plurality of the salient poles 51. As shown in FIGS. 2( a) and 2(b), each of the salient poles 51 is oppositely disposed through the upper case 12 in a direction perpendicular to the axial line “L” to the drive magnet 22 of the rotor 23 which is disposed within the partitioned chamber 20. The upper case 12 is disposed between the rotor 23 and the stator 29 to be functioned as a partition wall separating the pump chamber 25 from the stator 29.

The stator core 28 is structured so that a plurality of plate-shaped core pieces 52 having the same shape which are formed by die cutting a thin plate-shaped magnetic steel plate is laminated in the upper and lower direction and a laminated direction of the plate-shaped core pieces 52 is the axial line “L” direction. An inner peripheral face of the ring-shaped part 50 of the stator core 28 is formed with three inner side recessed parts 53 whose cross-sectional shape in a direction perpendicular to the axial line “L” is semicircular at an equal angular interval around the axial line “L”. Three inner side recessed parts 53 are the same shape and are extended in the axial line “L” direction. The depths in the radial direction of the respective inner side recessed parts 53 are the same and its cross-sectional shape is the same at each position in the axial line “L” direction.

In this embodiment, as shown in FIG. 3, an outer peripheral face of the tube shaped part 84 of the center protruded part 80 of the upper case 12 is formed with three stator fixing protruding parts 85 which are protruded to outer sides in a radial direction from parts in the circumferential direction. The stator fixing protruding parts 85 are press-fitted to the inner side recessed parts 53 of the ring-shaped part 50 and thereby the stator core 28 is fixed to the center protruded part 80. Further, the outer peripheral face of the tube shaped part 84 of the center protruded part 80 is formed with positioning parts 88 (see FIGS. 2( a) and 2(b) and FIG. 6( a)) at a position different from the stator fixing protruding parts 85 in the circumferential direction so as to be abutted with the ring-shaped part 50 of the stator core 28 from the underside in the axial line “L” direction to position the stator core 28 in the axial line “L” direction. After the stator fixing protruding parts 85 are press-fitted to the inner side recessed parts 53 of the ring-shaped part 50, the stator core 28 is abutted with the positioning parts 88 and is positioned in the axial line “L” direction.

Specifically, a cross-sectional shape perpendicular to the axial line “L” of each of three stator fixing protruding parts 85 formed on the outer peripheral face of the center protruded part 80 is a semicircular shape and three stator fixing protruding parts 85 are formed at an equal angular interval around the axial line “L” of the support shaft 24. Further, three stator fixing protruding parts 85 are formed to be the same shape as each other and are respectively extended in the axial line “L” direction along the outer peripheral face of the center protruded part 80 so as to be provided with a tapered face whose protruding amount to an outer side in the radial direction and to the circumferential direction is increased from a side of the bottom part 81 toward a side of the opening end, in other words, from the upper side to the lower side. The stator core 28 is fitted into the stator accommodating room 83 in a state that the stator fixing protruding parts 85 of the center protruded part 80 are to be inserted into the inner side recessed parts 53 of the ring-shaped part 50 and, after that, the lower end portions of the respective stator fixing protruding parts 85 are press-fitted to the inner side recessed parts 53 of the ring-shaped part 50 and thereby the stator core 28 is fixed to the upper case 12. In this embodiment, in a state that the lower end portion of the stator fixing protruding part 85 is press-fitted to the inner side recessed part 53 (of preferably one piece) of the ring-shaped part 50 of the plate-shaped core piece 52 structuring the stator core 28, the ring-shaped part 50 is abutted with the positioning part 88 and is fixed.

The base plate 30 is a circuit board on which electronic elements for controlling an exciting current to the drive coil 27 and the like are mounted. The base plate 30 is disposed in an upper space 87 which is provided on an inner side of a frame-shaped outer peripheral wall 86 protruding from an upper face of the upper case 12 to an upper side along its circumferential edge. The base plate 30 is provided with an opening part 30 a at its center portion and an upper face side of the bottom part 81 of the center protruded part 80 of the upper case 12 is protruded through the opening part 30 a. Therefore, the base plate 30 is disposed on a lower side in the axial line “L” direction with respect to the upper end of the bottom part 81. Further, the base plate 30 covers the stator 29 disposed within the stator accommodating room 83 from the upper side. A face on the stator core 28 side of the base plate 30 is connected with the lead wires 5 by soldering and a coil wire to the drive coil 27 is connected by soldering on the upper face side of the base plate 30 (opening side of the outer peripheral wall 86). The lead wires 5 are drawn out to an outer side of the pump case 2 through the wiring outlet part 6.

The wiring outlet part 6 is, as shown in FIG. 3, provided with a wiring outlet port 33 which is formed by cutting out an outer peripheral wall 86, a wire placing part 34 for arranging and placing in one row the lead wires 5 drawn out from the inner side of the pump case 2 to the outer side through the wiring outlet port 33, and a fixing member 35 which is fixed to the upper case 12 so as to close the wiring outlet port 33 from the upper side of the base plate 30 for sandwiching the lead wires 5 arranged on the wire placing part 34 between the wire placing part 34 and the fixing member 35 and thereby their coatings are fixed in a pressed state. The wiring outlet port 33 is opened toward the corner portion 2 g.

In this embodiment, as shown in FIGS. 1( a) and 1(b), a potting agent 16 as a sealing agent is poured into the stator accommodating room 83 and the upper space 87 of the upper case 12 so as to reach the upper face 2 a as the upper end of the outer peripheral wall 86 and thus the stator 29 and the base plate 30 are covered and fixed by the potting agent 16. In a case that an upper end face of the potting agent 16 is set to be at the same height or the lower position with respect to the upper face 2 a, when a cascade pump device 1 and another cascade pump device 1 are to be attached side by side or, when the cascade pump device 1 is to be attached to an external fixing member 101 as shown in FIGS. 9( a) and 9(b), the pump case 2 can be fixed to another cascade pump device 1 or the external fixing member 101 in an abutted state or in a close state and thus a mounting space of the cascade pump device 1 can be reduced. The potting agent 16 is resin having insulation property such as epoxy, acrylic, or silicon resin.

When an exciting current is supplied to the drive coil 27 from the connector 7 through the lead wires 5 and the base plate 30, the rotor 23 is rotated around the axial line “L”. As a result, liquid is sucked into the pump chamber 25 through the suction pipe 3, pressurized in the pump chamber 25 and then discharged from the discharge pipe 4. The motor (rotor 23, stator 29 and base plate 30) which drives the cascade pump device 1 in this embodiment is a three-phase brushless motor and three Hall elements not shown for detecting a position of the drive magnet 22 of the rotor 23 are disposed on the base plate 30. When the order of an exciting current supplied to the drive coil 27 is reversed, the rotor 23 is rotated in the reverse direction and thus, liquid is sucked through the discharge pipe 4, pressurized in the pump chamber 25 and then discharged from the suction pipe 3.

(Lower Case)

FIG. 5( a) is a perspective view showing the lower case 11 which is viewed from an upper side and FIG. 5( b) is a perspective view showing the lower case 11 which is viewed from a lower side. The lower case 11 is provided with a bottom plate part 61, a side wall part 62 which is stood up from an outer peripheral side portion of the bottom plate part 61 so as to extend to an upper side, and a circular recessed part 63 which is formed by the bottom plate part 61 and the side wall part 62. An under face of the bottom plate part 61 is the under face 2 b of the pump case 2. A contour shape of the side wall part 62 which is viewed in the axial line “L” direction is a substantially rectangular shape and a planar shape of the lower case 11 viewed in the axial line “L” direction is a substantially rectangular shape. The side wall part 62 is provided with a flat upper end face 62 a and the upper end face 62 a is an upper end face of the lower case 11. The pump chamber 25 is structured to be a ring shape along the circumferential edge of the circular recessed part 63. The support shaft fixing recessed part 60 is provided at the center of a circular bottom face of the circular recessed part 63.

A ring-shaped recessed part 64 is formed on an outer peripheral side of the support shaft fixing recessed part 60 coaxially with the support shaft fixing recessed part 60. A portion between the support shaft fixing recessed part 60 and the ring-shaped recessed part 64 is formed to be an inner side ring-shaped protruded face 65 and a portion on an outer peripheral side of the ring-shaped recessed part 64 is formed to be an outer side ring-shaped protruded face 66. The outer side ring-shaped protruded face 66 is formed with the lower side fluid flow passage 31 a structuring a bottom face of the pump chamber 25 and the lower side blocking part 32 a along its circumferential edge. A ring-shaped end face portion 67 of the outer side ring-shaped protruded face 66 which is adjacent to the inner side of the pump chamber 25 faces the disk part 40 of the rotor 23 which is disposed within the partitioned chamber 20 through a minute gap “G1” (see FIGS. 2( a) and 2(b)). In the circular ring-shaped end face portion 67, two grooves 67 a having a constant width by which the lower side fluid flow passage 31 a is in communication with the ring-shaped recessed part 64 are formed at positions separated from each other by 180°.

A ring-shaped stepped part 68 is provided on an upper side portion of the circular recessed part 63, in other words, on an inner peripheral face of an upper side portion of the side wall part 62. The ring-shaped stepped part 68 is provided with a ring-shaped end face 68 a, which is extended in the radial direction from a midway position in the axial line “L” direction of the inner peripheral face of the side wall part 62, and a circular inner peripheral face 68 b which is extended to an upper side from an outer circumferential edge of the ring-shaped end face 68 a. The ring-shaped stepped part 68 forms a circular recessed part having a diameter larger than a circular recessed part 63 on an upper end portion of the lower case 11.

The suction pipe 3 and the discharge pipe 4 are protruded in parallel from the front face 62 c of the side wall part 62. The inclined face 2 k and the hook 8 are provided at the corner portion 62 g on the front left side of the lower case 11 which is adjacent to the discharge pipe 4 of the side wall part 62. The hook 8 is formed along the inclined face 2 k and is formed on an inner side of a rectangular contour “R” of the side wall part 62 which is shown by the dotted line. In other words, the hook 8 is located on an inner side of a contour of a projecting corner which is structured by intersecting extended lines of the front face 2 c and the side face 2 d of the pump case 2 each other. Further, the hook 8 faces the inclined face 2 k through a space through which the lead wires 5 are capable of passing. A turning prevention recessed part 69 structuring the turning prevention mechanism 13 is provided at a corner portion 62 j on a rear right side of the side wall part 62. The turning prevention recessed part 69 is a recessed part which is recessed to a lower side from the upper end face 62 a. Further, the turning prevention recessed part 69 is cut out from the outer peripheral side and its inner peripheral face is exposed to the outer side of the lower case 11.

A lower case fixing part 14 a structuring the case fixing part 14 is protruded from the front face of the side wall part 62 to the front side between the suction pipe 3 and the discharge pipe 4. The lower case fixing part 14 a is formed with a first through hole 70(1) penetrating in the axial line “L” direction. Further, a corner portion 62 i (second fixing part) on the rear left side and a corner portion 62 j (third fixing part) on the rear right side of the side wall part 62 are respectively formed with a second through hole 70(2) penetrating in the axial line “L” direction and a third through hole 70(3) penetrating in the axial line “L” direction. The second through hole 70(2) is formed on the front side with respect to the attaching hole 9 at the corner portion 62 i on the rear left side and the third through hole 70(3) is formed on the front side with respect to the turning prevention recessed part 69 at the corner portion 62 j on the rear right side. In the corner portion 62 i on the rear left side and the corner portion 62 j on the rear right side of the side wall part 62, an under face portion where the second through hole 70(2) and the third through hole 70(3) are formed (under face portion of the bottom plate part 61) is formed with recessed parts 74 into which a head part of a headed screw is inserted when the lower case 11 and the upper case 12 are fixed to each other by the headed screw. In the corner portion 62 h on the front right side and the corner portion 62 i on the rear left side of the side wall part 62, an under face portion where the attaching hole 9 is formed (under face portion of the bottom plate part 61) is formed with a recessed part 75 into which a head part of a headed screw is inserted when the cascade pump device is fixed to an external apparatus by a headed screw.

(Upper Case)

FIG. 6( a) is a perspective view showing the upper case 12 which is viewed from an upper side and FIG. 6( b) is a perspective view showing the upper case 12 which is viewed from a lower side. The upper case 12 is, as shown in FIG. 6( a), provided with a center protruded part 80, a cylindrical tube part 89, which is coaxially structured with the center protruded part 80, and an inner side ring-shaped part 90 which connects an opening end of the center protruded part 80 with a lower end part of the cylindrical tube part 89. Further, the upper case 12 is, as shown in FIG. 6( b), provided with a ring-shaped protruded part 91, which is coaxially structured with the center protruded part 80 and the cylindrical tube part 89 on an outer peripheral side of the cylindrical tube part 89 and is protruded to a lower side, an outer side ring-shaped part 92, which connects an upper end part of the cylindrical tube part 89 with an upper end part of the ring-shaped protruded part 91, and a projecting part 93 which projects from an upper end part of the ring-shaped protruded part 91 to an outer peripheral side. The projecting part 93 is provided with a flat lower end face 93 a.

The stator accommodating chamber 83 in which the stator 29 is disposed is structured of faces of the center protruded part 80, the cylindrical tube part 89 and the inner side ring-shaped part 90 on an opposite side with respect to the lower case 11. The center protruded part 80 is provided with a protruding portion 80 a, which is protruded to an upper side from an opening of the stator accommodating chamber 83, on a side of the bottom part 81. A thickness in the radial direction of the cylindrical tube part 89 is formed thinner than a thickness in the radial direction of the center protruded part 80. An outer peripheral wall 86 which partitions the upper space 87 in which the base plate 30 is disposed is formed on the upper face of the projecting part 93.

A ring-shaped lower end face 94 (ring-shaped tip end face) of the ring-shaped protruded part 91 is formed with an upper side fluid flow passage 31 b and an upper side blocking part 32 b, which structures a ceiling face of the pump chamber 25, at a midway position in the radial direction. In the ring-shaped lower end face 94, a ring-shaped end face portion 94 a which is adjacent to an inner side of the pump chamber 25 faces the disk part 40 of the rotor 23 disposed within the partitioned chamber 20 through a minute gap “G2” (see FIGS. 2( a) and 2(b)).

A radial direction protruded part 96 protruding to an outer side by a predetermined dimension in the radial direction is provided on an upper end portion of a circular outer peripheral face 95 of the ring-shaped protruded part 91. The radial direction protruded part 96 is provided with a ring-shaped end face 96 a, which is extended to an outer side in the radial direction from a midway position in the axial line “L” direction of the ring-shaped protruded part 91 so as to face the lower case 11, and a circular outer peripheral face 96 b which is extended to an upper side from an outer circumferential edge of the ring-shaped end face 96 a so as to face the outer side in the radial direction.

A contour shape of the projecting part 93 is a roughly rectangular shape and the corner portion 93 g on the front left side is cut out obliquely to form the inclined face 2 k. The outer peripheral wall 86 is, as shown in FIG. 6( a), protruded to the upper side from an outer circumferential edge of the projecting part 93 except the corner portion 93 g having the cut-out portion. In the corner portion 93 g on the front left side having the cut-out portion, the outer peripheral wall 86 is provided at a setback position (inner position) from an outer circumferential edge of the projecting part 93 so as to incline to an inner side in the widthwise direction of the device toward the front side. Further, in the corner portion 93 g on the front left side, the outer peripheral wall 86 is cut out with a constant width in a rectangular shape and the cut-out part is formed as the wiring outlet port 33. A portion between the wiring outlet port 33 and the outer circumferential edge of the projecting part 93 is formed as the wire placing part 34. An upper face of the wire placing part 34 is formed with wire holding grooves 36 a whose cross section is a circular arc shape and which are extended in parallel to an outer side in the radial direction so as to correspond to the number of the lead wires 5. Circular arc grooves 37 are formed on an inner side of the wiring outlet port 33 so as to extend on the extension of the wire holding grooves 36 a.

In this embodiment, the fixing member 35 structuring the wiring outlet part 6 together with the wire placing part 34 is, as shown in FIG. 3, formed in a planar shape which is wider than an opening width of the wiring outlet port 33 and a pair of fitting grooves 38 is formed on one edge and the other edge in the widthwise direction of the device. The fitting grooves 38 are disposed on the same straight line and are opened so as to direct an opposite side to each other. Further, an under face of the fixing member 35 is formed with wire holding grooves 36 b whose cross section is in a circular arc shape at facing positions to the circular arc grooves of the wire placing part 34. In a state that the fixing member 35 is fixed to the upper case 12, circular openings formed by the wiring line holding grooves 36 a on the upper face of the wire placing part 34 and the wiring line holding grooves 36 b on the under face of the fixing member 35 are visually observed when the pump case 2 is viewed in the protruding direction of the suction pipe 3 and the discharge pipe 4 (see FIG. 1( c)).

When the lead wires 5 are to be taken out from the inside of the pump case 2, the lead wires 5 are arranged on the wire placing part 34 and then the fixing member 35 is fixed to the upper case 12 from an upper side of the upper case 12 so that wing wall parts of the wiring outlet port 33 of the outer peripheral wall 86 (end parts of an opening of the outer peripheral wall 86 which is cut out with a constant width) are inserted into a pair of the fitting grooves 38. As a result, a narrowed portion 39 between a pair of the fitting grooves 38 is press-fitted into the wiring outlet port 33 and the lead wires 5 are inserted and sandwiched between the wire holding grooves 36 a of the wire placing part 34 and the wire holding grooves 36 b of the fixing member 35 and are fixed in a state that their coatings are pressed.

Further, an edge portion on the inner peripheral side of the fixing member 35 is superposed on an outer circumferential edge portion of the base plate 30 from the upper side and the base plate 30 is prevented from being detached. In this case, the edge portion on the inner peripheral side of the fixing member 35 and the base plate 30 are disposed so as to be close to each other or abutted with each other.

In this embodiment, the lead wires 5 are inserted and sandwiched between the wiring line holding grooves 36 a of the wire placing part 34 and the wiring line holding grooves 36 b of the fixing member 35 and a drawing-out direction (wiring line drawing-out direction) “D1” of the lead wire 5 is determined. In other words, a wiring line drawing-out guide part 6 a which determines a drawing-out direction “D1” of the lead wire 5 is structured by the wiring line holding groove 36 a of the wire placing part 34 and the wiring line holding groove 36 b of the fixing member 35 (see FIG. 1( c)). The drawing-out direction “D1” of the lead wire 5 by the wiring line drawing-out guide part 6 a is set to be at an angle less than 90° with respect to the protruding direction of the suction pipe 3 and the discharge pipe 4 around the axial line “L” and, in this embodiment, at an angle of about 45°. When the lead wires 5 are inserted and sandwiched between the wiring line holding grooves 36 a of the wire placing part 34 and the wiring line holding grooves 36 b of the fixing member 35, the lead wires 5 taken out to the outer side of the pump case 2 from the wiring outlet part 6 are, as shown in FIGS. 1( a), 1(b) and 1(c), extended in a direction at an angle less than 90° with respect to the protruding direction of the suction pipe 3 and the discharge pipe 4 and thus the lead wires 5 are easily extended toward the front side of the cascade pump device 1. Further, when the drawing-out direction “D1” of the lead wires 5 is set to be at an angle less than 90° with respect to the protruding direction of the suction pipe 3 and the discharge pipe 4, in comparison with a case that the drawing-out direction “D1” of the lead wires 5 is set to be at an angle of 90° with respect to the protruding direction of the suction pipe 3 and the discharge pipe 4, a space for taking out the lead wires 5 toward the front side of the cascade pump device 1 can be restrained small in the widthwise direction of the cascade pump device 1.

A turning preventing protruding part 97 in a cylindrical shape which structures the turning prevention mechanism 13 together with the turning prevention recessed part 69 is, as shown in FIG. 6( b), protruded to a lower side from the corner portion 93 j on the rear right side of the projecting part 93. An outer circumferential edge of a tip end face 97 a (lower end face) of the turning preventing protruding part 97 is chamfered. In this embodiment, a position of the tip end face 97 a of the turning preventing protruding part 97 is set to be the same position as the ring-shaped lower end face 94 of the ring-shaped protruded part 91 in the axial line “L” direction. Further, a protruding dimension of the turning preventing protruding part 97 is set to be shorter than a depth dimension of the turning prevention recessed part 69. In addition, when the turning preventing protruding part 97 is fitted to the turning prevention recessed part 69, the turning preventing protruding part 97 is abutted with the inner peripheral face, specifically, the side face of the turning prevention recessed part 69 in the circumferential direction around the axial line “L” without a gap space and, in the radial direction with the axial line “L” as a center, a gap space is formed between the peripheral face of the turning prevention recessed part 69 and the turning preventing protruding part 97.

An upper case fixing part 14 b structuring the case fixing part 14 is protruded to the front side from the front face (front side) of the projecting part 93 at a center in the widthwise direction of the device. The upper case fixing part 14 b is provided with a screw hole 98(1) which is recessed in the axial line “L” direction. Further, the corner portion 93 i (second fixing part) on the rear left side and the corner portion 93 j (third fixing part) on the rear right side are respectively provided with a second screw hole 98(2) recessed in the axial line “L” direction and a third screw hole 98 (3) recessed in the axial line “L” direction. The second screw hole 98(2) is formed on the front side of the attaching hole 9 at the corner portion 93 i on the rear left side and the third screw hole 98(3) is formed on the front side of the turning preventing protruding part 97 at the corner portion 93 j on the rear right side.

(Partitioning of Pump Chamber)

FIG. 7 is a sectional view showing a part of the cascade pump device 1 which is cut by the “Z-Z” line in FIG. 1( a) and which is a state that the ring-shaped protruded part 91 of the upper case 12 is to be inserted into the inner side of the ring-shaped stepped part 68 of the lower case 11. When the pump chamber 25 (partitioned chamber 20) is to be partitioned, an O-ring 26 is mounted on the outer peripheral face 95 of the ring-shaped protruded part 91 of the upper case 12. In this case, a lubricant is applied to the O-ring 26. Further, the support shaft 24 is previously fixed to the support shaft fixing recessed part 82 of the upper case 12. The rotor 23 is disposed in the circular recessed part 63 of the lower case 11 so that the support shaft 24 is capable of being inserted into the bearing part 41.

Next, the ring-shaped protruded part 91 of the upper case 12 is inserted into the inner side of the ring-shaped stepped part 68 of the lower case 11. In this embodiment, the tip end face 97 a of the turning preventing protruding part 97 of the turning prevention mechanism 13 is set to be at the same position as the ring-shaped lower end face 94 of the ring-shaped protruded part 91 in the axial line “L” direction. Therefore, when the ring-shaped protruded part 91 is inserted into the inner side of the ring-shaped stepped part 68, the turning preventing protruding part 97 is simultaneously inserted into the turning prevention recessed part 69 which is provided in the lower case 11.

After that, the upper case 12 and the lower case 11 are relatively come close to each other so that the ring-shaped lower end face 94 of the ring-shaped protruded part 91 (ring-shaped end face portion which is located on the outer peripheral side with respect to the upper side fluid flow passage 31 b and the upper side blocking part 32 b) is abutted with the ring-shaped end face 68 a of the ring-shaped stepped part 68 of the lower case 11. In this case, the circular outer peripheral face 96 b of the radial direction protruded part 96 of the upper case 12 is abutted with the circular inner peripheral face 68 b of the ring-shaped stepped part 68 of the lower case 11 and thus the upper case 12 is positioned in the radial direction by the lower case 11. Further, the O-ring 26 is crushed in the radial direction between the circular outer peripheral face 95 of the ring-shaped protruded part 91 of the upper case 12 and the circular inner peripheral face 68 b in the radial direction of the lower case 11 in a sandwiched state between the ring-shaped end face 96 a of the radial direction protruded part 96 and the ring-shaped end face 68 a of the ring-shaped stepped part 68. As a result, the leakage of fluid from the partitioned chamber 20 is prevented.

When the upper case 12 is superposed on the lower case 11 to form the pump chamber 25 (partitioned chamber 20) in a partitioned state, the lower end of the support shaft 24 penetrated through the bearing part 41 of the rotor 23 is inserted and fixed to the support shaft fixing recessed part 60 of the lower case 11 and the support shaft 24 and the center protruded part 80 are set to be in a coaxial state. Therefore, the stator 29 and the rotor 23 are coaxially disposed with each other and the salient poles 51 around which the drive coil 27 is wound in the stator core 28 face the drive magnet 22 of the rotor 23 disposed in the partitioned chamber 20 through the cylindrical tube part 89 of the upper case 12. In this embodiment, as shown in FIGS. 2( a) and 2(b), two washers 43 are fitted between the upper end face of the bearing part 41 of the rotor 23 and the bottom part 81 of the protruded part and thereby the magnetic center position in the axial line “L” direction of the drive magnet 22 mounted on the rotor 23 is shifted to a lower side with respect to the magnetic center position in the axial line “L” direction of the stator core 28. As a result, the rotor 23 is urged upward by a magnetic attraction force acted between the stator core 28 and the drive magnet 22.

After that, the upper case 12 and the lower case 11 are fixed to each other by three headed screws which penetrate through the first through third through holes 70(1) through 70(3) provided in the lower case 11 and are threadedly engaged with the first through third screw holes 98(1) through 98(3) provided in the upper case 12.

In a state that the pump chamber 25 is partitioned, as shown in FIG. 1( b), a gap space “G3” is formed between the tip end part of the turning preventing protruding part 97, which is fitted to the turning prevention recessed part 69, and the bottom face 69 a of the turning prevention recessed part 69. Therefore, when a flat tip screwdriver or the like is inserted into the gap space “G3” between the tip end part of the turning preventing protruding part 97 fitted to the turning prevention recessed part 69 and the bottom face of the turning prevention recessed part 69 from the outer side of the pump case 2 and, after that, a force is applied in a direction separating the tip end part of the turning preventing protruding part 97 from the bottom face of the turning prevention recessed part 69, the pump case 2 is disassembled to the upper case 12 and the lower case 11.

(Drawing-Out of Lead Wire)

Next, embodiments of a method for drawing out the lead wires 5 which are taken out from the wiring outlet part 6 to an outer side of the pump case 2 will be described below with reference to FIGS. 8( a), 8(b) and 8(c). FIGS. 8( a), 8(b) and 8(c) are explanatory views showing a state that lead wires (wiring lines) are drawn out. FIG. 8( a) shows an embodiment in which the lead wires 5 are extended to the front side of the pump case 2, FIG. 8( b) shows an embodiment in which the lead wires 5 are drawn out along the inclined face 2 k, and FIG. 8( c) shows an embodiment in which the lead wires 5 are bent in a direction separated from the pump case 2 by utilizing the hook 8.

In the embodiment shown in FIG. 8( a), the lead wires 5 taken out from the wiring outlet part 6 are drawn out to the front side (protruding direction of the suction pipe 3 and the discharge pipe 4). In this embodiment, the wiring outlet part 6 is provided at the corner portion 2 g on the front left side of the pump case 2, and the wiring outlet part 6 is directed to the outer side in the radial direction toward the obliquely front side, and the drawing-out direction “D1” of the lead wires 5 through the wiring line drawing-out guide part 6 a is set to be about 45° with respect to the protruding direction of the suction pipe 3 and the discharge pipe 4 around the axial line “L”. Therefore, when the lead wires 5 taken out from the wiring outlet part 6 are drawn out to the front side, the lead wires 5 can be arranged within a range of a width of the pump case 2 (between a pair of imaginary lines “L1” which are in parallel to the suction pipe 3 and the discharge pipe 4 and are circumscribed with the pump case 2 when viewed in the axial line direction). Further, hoses 100 connected with the suction pipe 3 and the discharge pipe 4 can be disposed within a range of a width of the pump case 2 on the front side of the pump case 2.

In other words, the wiring outlet part 6 is located on the inner side of a contour of the projecting corner (see the rectangular contour “R” in FIG. 5( a)) which is structured by extending and intersecting the front face 2 c and the side face 2 d structuring a part of the contour of the pump case 2 when viewed in the axial line “L” direction. Further, the drawing-out direction “D1” of the lead wires 5 drawn out to the outer side through the wiring outlet part 6 is determined to the front side by the wiring line drawing-out guide part 6 a structured by the wiring line holding grooves 36 a and the wiring line holding grooves 36 b. Therefore, the lead wires 5 can be drawn out to the front side within a range in the widthwise direction of the pump case 2.

In this embodiment, three side faces 2 d, 2 e and 2 f of the pump case 2, i.e., the side face 2 d on the front left side, the side face 2 e on the front right side and the side face 2 f on the rear side except the front face 2 c where the suction pipe 3 and the discharge pipe 4 are provided are formed in a flat face. Therefore, in a case that a plurality of the cascade pump devices 1 is adjacently disposed in the widthwise direction of the cascade pump device 1 in a plane perpendicular to the axial line “L” or adjacently disposed in a rear direction of the cascade pump device 1, the plurality of the cascade pump devices 1 can be arranged in a small area without a space between the cascade pump device 1 and another cascade pump device 1.

In the embodiment shown in FIG. 8( b), the lead wires 5 which are taken out through the wiring outlet part 6 are bent from the wire placing part 34 along the inclined face 2 k downward. The lead wires 5 are inserted between the hook 8 and the inclined face 2 k and are locked by the hook 8 and thus the lead wires 5 are not floated from the inclined face 2 k. In this embodiment, the inclined face 2 k is provided by obliquely cutting the corner portion 2 g on the front left side of the pump case 2 and, when the pump case 2 is viewed in the axial line “L” direction, the hook 8 is located on an inner side of a rectangular contour formed by four side faces 2 c through 2 f. Therefore, the lead wires 5 drawn out downward along the inclined face 2 k are drawn out on an inner side of the rectangular contour.

In the embodiment shown in FIG. 8( c), the lead wires 5 drawn out downward in FIG. 8( b) are bent by utilizing the hook 8 from a portion contacted with the hook 8 in a direction separated from the pump case 2. The hook 8 is extended in a direction perpendicular to the axial line “L” along the inclined face 2 k with a constant width at a center position in the axial line “L” direction of the inclined face 2 k. Therefore, when the lead wires 5 are to be bent in a direction separated from the pump case 2, the lead wires 5 can be bent and drawn out within a range of a height of the pump case 2, in other words, the lead wires 5 can be bent at a position so as not to protrude from a space between a pair of the upper faces 2 a and the under face 2 b of the pump case 2 facing in the axial line “L” direction.

(Operation and Effect)

According to the embodiments described above, the suction pipe 3 and the discharge pipe 4 which are extended in parallel to each other and the wiring outlet part 6 are provided at the intermediate part 2 z between the upper face 2 a and the under face 2 b of the pump case 2 formed in a rectangular prism shape and the drawing-out direction “D1” of the lead wires 5 drawn out to the outer side through the wiring outlet part 6 is set to be at an angle less than 90° with respect to the protruding direction of the suction pipe 3 and the discharge pipe 4. Therefore, when the pump case 2 is viewed in the protruding direction of the suction pipe 3 and the discharge pipe 4, all of the suction pipe 3, the discharge pipe 4 and the wiring outlet part 6 are disposed so as to be capable of being visually observed. Accordingly, in order to mount the cascade pump device 1 on an external apparatus, it is sufficient that a space for drawing out pipes such as a hose connected with the suction pipe 3 and the discharge pipe 4 and a space for drawing out the lead wires 5 drawn out from the pump case 2 are provided on the front side (one side) of the pump case 2. In other words, a space for drawing out the lead wires 5 is not required on the rear side (the other side) of the pump case 2 and thus the mounting space can be restrained. Further, the wiring outlet part 6 is provided at the intermediate part 2 z between the upper face 2 a and the under face 2 b which are located at both ends in the axial line “L” direction of the pump case 2 and thus the lead wires 5 are taken out within a range of the height in the axial line “L” direction of the pump case 2. Therefore, a space for drawing out the lead wires 5 is not required at a position adjacent to the pump case 2 in the axial line “L” direction and thus the mounting space is restrained.

In addition, the pump case 2 is structured in a rectangular prism shape and thus, when the cascade pump device 1 is to be mounted, occurrence of a useless space between the cascade pump device 1 and an external apparatus is reduced. Therefore, for example, in a case that a plurality of the cascade pump devices 1 are disposed in parallel to each other in the widthwise direction of the device, the side face (second side face) 2 d of one cascade pump device 1 and the side face (third side face) 2 e of the other cascade pump device 1 adjacent to each other can be abutted with each other or set to be in a close state. Further, in a case that a plurality of the cascade pump devices 1 are disposed in the upper and lower direction, the upper face 2 a of one cascade pump device 1 and the under face 2 b of the other cascade pump device 1 adjacent to each other are abutted with each other or set to be in a close state.

Further, in the embodiments described above, the suction pipe 3, the discharge pipe 4 and the wiring outlet part 6 are disposed at the intermediate part 2 z within which the pump chamber 25 is structured around the axial line “L” in the order of the suction pipe 3, the discharge pipe 4, and the wiring outlet part 6. Therefore, an angle around the axial line “L” from the suction pipe 3 to the discharge pipe 4 (angular range of the lower side fluid flow passage 31 a and the upper side fluid flow passage 31 b) are set to be large and thus a pressure for pressure-feeding liquid is enhanced. Accordingly, even when the wiring outlet part 6 for drawing out the lead wires 5 is provided toward the protruding direction of the suction pipe 3 and the discharge pipe 4, increase of the size of the pump case 2 can be restrained. In addition, in the cascade pump device 1 in this embodiment, the suction pipe 3 and the discharge pipe 4 are exchanged by changing the rotating direction of the rotor 23. In other words, fluid is sucked from a side of the discharge pipe 4 and the fluid is discharged from a side of the suction pipe 3. In this case, the suction pipe 3, the discharge pipe 4 and the wiring outlet part 6 are disposed around the axial line “L” in the order of the discharge pipe 4, the suction pipe 3 and the wiring outlet part 6.

The cascade pump device 1 in this embodiment is capable of being fixed to an external apparatus 200 by using a fixing member whose cross section is in an “L”-shape. FIGS. 9( a) and 9(b) are explanatory views showing a state that the cascade pump device is attached to an external apparatus by using a fixing member. The fixing member 101 is, as shown in FIGS. 9( a) and 9(b), provided with a rectangular mounting plate part 101 a which is fixed to the upper face 2 a of the pump case 2 by utilizing the attaching holes 9 of the cascade pump device 1 and a rectangular fixing plate part 101 b which is bent from an edge of the mounting plate part 101 a in a direction perpendicular to the mounting plate part 101 a and is fixed to the external apparatus 200.

In a case that the cascade pump device 1 is to be attached to an external apparatus 200 by using the fixing member 101, for example, as shown in FIG. 9( a), the cascade pump device 1 is attached to the external apparatus 200 so that the side face 2 e is directed to a lower side to be abutted with the external apparatus 200. In this case, according to the cascade pump device 1 in this embodiment, the lead wires 5 can be drawn out from the second side face 2 d so as not to protrude upward (outer side). In other words, in a case that the cascade pump device 1 is longitudinally placed so that a projected area of the pump case 2 when viewed from an upper side is small, the height of the cascade pump device 1 including the lead wires 5 can be restrained low. Alternatively, the cascade pump device 1 may be attached to the external apparatus 200 so that the side face 2 d of the pump case 2 is directed to a lower side to be abutted with the external apparatus 200. Also in this case, according to the cascade pump device 1 in this embodiment, the lead wires 5 can be drawn out without interfering with the external apparatus 200.

Further, in a case that the cascade pump device 1 is attached to the external apparatus 200 by using the fixing member 101, as shown in FIG. 9( b), the cascade pump device 1 may be attached to the external apparatus 200 so that the side face 2 f of the pump case 2 is directed to a lower side to be abutted with the external apparatus 200. In other words, according to the cascade pump device 1 in this embodiment, since the wiring outlet part 6 is provided on a side where the suction pipe 3 and the discharge pipe 4 are protruded and thus the lead wires 5 are not protruded to a side of the side face 2 f which is opposite to the front face 2 c from which the suction pipe 3 and the discharge pipe 4 are protruded and the side face 2 f can be tightly contacted with the external apparatus 200. As described above, in the cascade pump device 1 in this embodiment, even when either of the upper face 2 a, the under face 2 b, and the side faces 2 d through 2 f of the pump case 2 is used as an abutting face (opposing face) with the external apparatus 200, the pump case 2 can be tightly contacted with the external apparatus 200 and thus a degree of freedom of an arrangement of the cascade pump device 1 is enhanced.

In addition, according to the embodiments described above, the hook 8 for locking the lead wire 5 is located on an inner side of the rectangular contour which is structured of four side faces 2 c through 2 f when the pump case 2 is viewed in the axial line “L” direction and thus, in a case that the pump case 2 is to be mounted on an external apparatus 200, the hook 8 is prevented from interfering with the external apparatus 200. Further, in a case that the lead wires 5 are drawn out along the inclined face 2 k, when the pump case 2 is viewed in the axial line “L” direction, the lead wires 5 can be located on an inner side of the rectangular contour structured of four side faces 2 c through 2 f. In addition, when the hook 8 is utilized for bending the lead wires 5 in a direction separated from the pump case 2, the lead wires 5 can be bent and drawn out at a position which is not protruded from a range of the height of the pump case 2.

Further, in the embodiments described above, the attaching holes 9 are formed at the corner portion 2 h on the front right side and the corner portion 2 i on the rear left side of the pump case 2 in a rectangular prism shape for attaching the pump case 2 to the external apparatus 200. Each of the attaching holes 9 is provided in the pump case 2 formed in a rectangular prism shape by utilizing a corner portion which is a dead space for the circular ring-shaped pump chamber 25 and thus, even when the attaching holes 9 are provided, the size of the pump case 2 is not increased. In addition, in this embodiment, the wiring outlet part 6 is provided at the corner portion 2 g adjacent to one side in the widthwise direction of the front face 2 c of the device, the attaching hole 9 is provided at the corner portion 2 h adjacent to the other side of the front face 2 c, and the attaching hole 9 is provided at the corner portion 2 i which is located at a diagonal position to the corner portion 2 h. Therefore, when the pump case 2 is to be attached to the external apparatus or the fixing member 101 by utilizing two attaching holes 9, forces applied to the pump case 2 can be easily made uniform and the cascade pump device 1 is prevented from occurring a mounting failure such as floating from the external apparatus.

In addition, the case fixing part 14 for fixing the lower case 11 and the upper case 12 to each other with a screw is protruded from the front face 2 c between the suction pipe 3 and the discharge pipe 4. A portion between the suction pipe 3 and the discharge pipe 4 is a dead space when the cascade pump device 1 is attached to an external apparatus 200 and thus, in a case that the case fixing part 14 is protruded at that position, when the cascade pump device 1 is to be mounted on the external apparatus 200, the case fixing part 14 does not interfere with the external apparatus 200. Further, the second through hole 70(2) and the second screw hole 98(2), which structure the second fixing part and the third through hole 70(3) and the third screw hole 98(3) which structure the third fixing part for fixing the lower case 11 and the upper case 12 to each other with a screw are formed at the corner portion 2 i on the rear left side and the corner portion 2 j on the rear right side. In other words, the second through hole 70(2) and the second screw hole 98(2), and the third through hole 70(3) and the third screw hole 98(3) are provided by utilizing a corner portion which is a dead space with respect to the circular ring-shaped pump chamber 25 in the pump case 2 formed in a rectangular prism shape. Therefore, even when the second and the third fixing parts are provided, the size of the pump case 2 is not increased.

Further, in the embodiments described above, when the lower case 11 and the upper case 12 are to be superposed on each other to partition the pump chamber 25, the turning prevention mechanism 13 is provided for preventing the lower case 11 from relatively turning to the upper case 12 around the axial line “L”. The turning prevention mechanism 13 is provided by utilizing a corner portion which is a dead space with respect to the circular ring-shaped pump chamber 25 in the pump case 2 formed in a rectangular prism shape. Therefore, even when the turning prevention mechanism 13 is provided, the size of the pump case 2 is not increased.

According to the embodiments described above, since the suction pipe 3 and the discharge pipe 4 are extended in parallel to each other, the lower case 11 can be molded by using the same slide die.

Other Embodiments

In the embodiments described above, the pump case 2 is formed in a rectangular prism shape. However, the pump case may be formed in a cylindrical shape, or in a polygonal prism shape such as a triangular prism shape, a pentagonal prism shape, or a hexagonal cylinder shape. Even in a case that such a shape is adopted, when the suction pipe and the discharge pipe extended in the same direction in parallel to each other and the wiring outlet part are provided between two end faces located at both ends in the axial line direction of the pump case and an angle between the drawing-out direction “D1” of the wiring line drawing-out guide part and the protruding direction of the suction pipe and the discharge pipe is less than 90°, a space can be secured for drawing out pipes such as a hose which are connected with the suction pipe and the discharge pipe on one side of the pump case from which the suction pipe and the discharge pipe are protruded and a space can be secured for drawing out the lead wires drawn out from the pump case on the one side of the pump case when the cascade pump device is to be mounted on the external apparatus. Further, the lead wires can be taken out within a range of the height in the axial line direction of the pump case. Therefore, a mounting space of the cascade pump device can be restrained.

Further, it may be structured that the pump case is not formed in a polygonal prism shape when the pump case is provided with the first side face and the second side face which are disposed adjacent to each other around the axial line “L” in the intermediate part to structure a part of the contour of the pump case 2 viewed in the axial line “L” direction and, when the pump case is provided with a projecting corner formed between the first side face and the second side face. Also in this case, as described above, when the suction pipe and the discharge pipe extended in the same direction in parallel to each other and the wiring outlet part are provided between two end faces located at both ends in the axial line direction of the pump case and an angle between the drawing-out direction “D1” of the wiring line drawing-out guide part and the protruding direction of the suction pipe and the discharge pipe is less than 90°, a space can be secured for drawing out pipes such as a hose which are connected with the suction pipe and the discharge pipe on one side of the pump case from which the suction pipe and the discharge pipe are protruded and a space can be secured for drawing out the lead wires drawn out from the pump case on the one side of the pump case when the cascade pump device is to be mounted on the external apparatus. Further, the lead wires can be taken out within a range of the height in the axial line direction of the pump case. Therefore, a mounting space of the cascade pump device can be restrained. Further, when the suction pipe and the discharge pipe protruding in parallel to each other are provided on the first side face and the wiring outlet part is provided at the projecting corner formed between the first side face and the second side face, a space can be secured for drawing out pipes such as a hose which are connected with the suction pipe and the discharge pipe and a space can be secured for drawing out the lead wires drawn out from the pump case on one side of the pump case when the cascade pump device 1 is to be mounted on an external apparatus. Further, the lead wires can be taken out within a range of the height in the axial line direction of the pump case. Therefore, a mounting space of the cascade pump device can be restrained. Further, the wiring outlet part is disposed in a dead space between the circular ring-shaped pump chamber and the projecting corner and thus the size of the pump case is prevented from being increased.

Further, in the embodiments described above, the hook 8 is used as the wiring line direction restricting part. However, for example, it may be structured that a protruded part provided with a through hole through which the lead wires 5 are passed is provided on the inclined face 2 k to utilize as the wiring line direction restricting part.

In addition, in the embodiments described above, the wiring line drawing-out guide part 6 a is structured of the wiring line holding grooves 36 a of the wire placing part 34 and the wiring line holding grooves 36 b of the fixing member 35. However, the wiring line drawing-out guide part 6 a may be structured of only the wiring line holding grooves 36 a of the wire placing part 34. In this case, the lead wires 5 are placed on the wiring line holding grooves 36 a and are fixed by pressing down the lead wires 5 from an upper side by using the fixing member which is not provided with the wiring line holding grooves 36 b. Further, it may be structured that, after the lead wires 5 are placed on the wiring line holding grooves 36 a, the lead wires 5 are temporarily fixed by using a fixing jig and then the lead wires 5 are fixed to the wiring line holding grooves 36 a with an adhesive or a potting agent 16.

Further, in the embodiments described above, the wiring line drawing-out guide part 6 a is structured of a pair of the grooves which are oppositely disposed to each other (the wiring line holding grooves 36 a and the wiring line holding grooves 36 b). However, the upper case 12 or the fixing member 35 may be provided with holes through which the lead wires 5 are individually passed, or provided with a hole through which all of the lead wires 5 are passed to set the drawing-out direction “D1” of the lead wires 5. Further, it may be structured that a plurality of ribs is formed on the wire placing part 34 and the lead wires 5 are disposed between respective ribs to determine the drawing-out direction “D1” of the lead wires 5.

In addition, in the embodiments described above, the wiring outlet part 6 is provided at the corner portion 2 g which is a projecting corner between the front face 2 c and the side face 2 d of the pump case 2. However, the wiring outlet part 6 may be provided at the corner portion 2 h which is a projecting corner between the front face 2 c and the side face 2 e. Further, the wiring outlet part 6 may be provided at the corner portion 2 g and the corner portion 2 h so that the lead wires 5 are taken out through two positions.

In accordance with an embodiment of the present invention, the front face 2 c and the side faces 2 d, 2 e and 2 f may be formed in a curved shape in which a center part in the widthwise direction or the height direction of the entire side face or a part of the side face is bulged to an outer side. Further, a stepped shape may be formed between the outer side face of the side wall part 62 of the lower case 11 and the outer side face of the outer peripheral wall 86 of the upper case 12 in the axial line “L” direction. Also in the case structured as described above, when the wiring outlet part 6 is disposed on an inner side with respect to the contour of the pump case 2 viewed in the axial line “L” direction, a space near the contour of the pump case 2 for drawing out the lead wires 5 taken out through the wiring outlet part 6 can be made small. Therefore, when the cascade pump device 1 is to be mounted, interference of an external apparatus with the lead wires 5 can be restrained.

While the description above refers to particular embodiments of the present invention, it will be understood that many modifications may be made without departing from the spirit thereof. The accompanying claims are intended to cover such modifications as would fall within the true scope and spirit of the present invention.

The presently disclosed embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims, rather than the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. 

1. A cascade pump device comprising: a pump chamber which is formed in a circular ring shape; an impeller which is formed in a circular ring shape and is coaxially disposed within the pump chamber; a magnetic drive mechanism which is structured to rotate the impeller by exciting a drive coil; and a pump case which accommodates the pump chamber, the impeller and the magnetic drive mechanism; wherein the pump case is provided with two end faces which are located at both ends in an axial line direction and an intermediate part between the two end faces; wherein the intermediate part is provided with a suction pipe and a discharge pipe which are in communication with the pump chamber and a wiring outlet part for taking out wiring lines for supplying an exciting current to the drive coil to an outer side; wherein the suction pipe and the discharge pipe are protruded in a same direction which is parallel to each other along a plane perpendicular to the axial line direction; wherein the wiring outlet part is provided with a wiring line drawing-out guide part which determines a drawing-out direction of the wiring lines to the outer side; and wherein an angle between the drawing-out direction and a protruding direction of the suction pipe and the discharge pipe is less than 90° around the axial line.
 2. The cascade pump device according to claim 1, wherein the suction pipe, the discharge pipe and the wiring outlet part are provided around the axial line direction in an order of the suction pipe, the discharge pipe and the wiring outlet part, or in an order of the discharge pipe, the suction pipe and the wiring outlet part.
 3. The cascade pump device according to claim 1, wherein the intermediate part is provided with an outer peripheral face structuring a contour of the pump case when viewed in the axial line direction, and the wiring outlet part is provided on an inner side with respect to the outer peripheral face structuring the contour.
 4. The cascade pump device according to claim 1, wherein the intermediate part is provided with a first side face and a second side face, which are adjacent to each other around the axial line direct and structure a part of a contour of the pump case when viewed in the axial line direction, and a first projecting corner which is formed between the first side face and the second side face, the magnetic drive mechanism is structured on an inner side in a radial direction with respect to the pump chamber, the suction pipe and the discharge pipe are protruded from the first side face, and the wiring outlet part is provided on an inner side with respect to the first projecting corner.
 5. The cascade pump device according to claim 4, further comprising an inclined face extending in the axial line direction and intersecting with the first side face and the second side face, wherein the inclined face is formed at the first projecting corner by cutting out a tip end of the first projecting corner.
 6. The cascade pump device according to claim 5, wherein the intermediate part is provided with a wiring line direction restricting part which restricts a direction of the wiring line drawn out along the inclined face after the wiring line is taken out from the wiring outlet part to an outer side of the pump case, and the wiring line direction restricting part is located on an inner side of a contour of a projecting corner structured by extending and intersecting the first side face and the second side face each other.
 7. The cascade pump device according to claim 6, wherein the wiring line direction restricting part is extended in a direction perpendicular to the axial line direction along the inclined face at a midway position in the axial line direction of the inclined face.
 8. The cascade pump device according to claim 4, wherein the pump case is formed in a rectangular prism shape.
 9. The cascade pump device according to claim 8, wherein the first projecting corner is formed with an inclined face which intersects the first side face and the second side face and is extended in the axial line direction by cutting out a tip end of the first projecting corner, the intermediate part is provided with a wiring line direction restricting part which restricts a direction of the wiring line drawn out along the inclined face after the wiring line is taken out from the wiring outlet part to an outer side of the pump case, and the wiring line direction restricting part is a hook having a space for locking the wiring line between the inclined face and the hook and is located on an inner side of a contour of a projecting corner which is formed by extending and intersecting the first side face and the second side face each other.
 10. The cascade pump device according to claim 8, further comprising attaching holes for attaching the pump case to an external apparatus, wherein one of the attaching holes is formed on an inner side of a second projecting corner between the first side face and a third side face adjacent to the first side face on an opposite side to the second side face around the axial line direction in the pump case, and wherein another of the attaching holes is formed on an inner side of a third projecting corner located at a diagonal position to the second projecting corner.
 11. The cascade pump device according to claim 10, wherein the pump case includes a first case and a second case, the pump chamber is partitioned by superposing the first case and the second case on each other in a partially overlapped state in a direction perpendicular to the axial line direction, the pump case is provided with a first fixing part for fixing the first case and the second case to each other with a screw, and the first fixing part is protruded from the first side face between the suction pipe and the discharge pipe.
 12. The cascade pump device according to claim 10, further comprising a second fixing part and a third fixing part which are provided in the pump case for fixing the first case and the second case to each other with a screw, wherein the second fixing part is formed on an inner side of the third projecting corner and the third fixing part is formed on an inner side of the fourth projecting corner located at a diagonal position to the first projecting corner.
 13. The cascade pump device according to claim 10, wherein the pump case includes a first case and a second case, the pump chamber is partitioned by superposing the first case and the second case on each other in a partially overlapped state in a direction perpendicular to the axial line direction, an O-ring is coaxially disposed with the pump chamber between the first case and the second case for preventing leakage of fluid from the pump chamber, and a turning prevention mechanism is structured on an inner side of a fourth projecting corner located at a diagonal position to the first projecting corner in the pump case for preventing the first case and the second case from relatively turning to each other around the axial line direction when the first case and the second case are to be superposed on each other to partition the pump chamber.
 14. A pump case configured to accommodate a pump chamber, an impeller, and a magnetic drive mechanism, the pump case comprising: two end faces, each of which are located at ends of the pump case in an axial line direction; and an intermediate part between the two end faces; wherein the intermediate part is provided with a suction pipe and a discharge pipe which are in communication with the pump chamber, and a wiring outlet part for taking out wiring lines for supplying a current to the magnetic drive mechanism to an outer side; wherein the suction pipe and the discharge pipe are protruded in a same direction which is parallel to each other along a plane perpendicular to the axial line direction; wherein the wiring outlet part is provided with a wiring line drawing-out guide part which determines a drawing-out direction of the wiring lines to the outer side; and wherein an angle between the drawing-out direction and a protruding direction of the suction pipe and the discharge pipe is less than 90° around the axial line. 